People with Fetal Alcohol Syndrome (FAS) exhibit striking deficits in social behavior; these alterations in social behavior are independent of chances in intelligence and may be very damaging with respect to day- to-day functioning. The goal of this proposal is to use a model of FAS in which the rat is exposed to alcohol during all three trimester equivalents to investigate the mechanism by which alcohol alters social behaviors in the rat. The model that is used is novel and exposes rats to alcohol during all three trimester equivalents or, in other words, during both the prenatal and postnatal periods. The first set of experiments characterizes the model by comparing the effects of alcohol exposure during the prenatal period alone, the postnatal period alone and the combination of prenatal and postnatal periods alone on activity, passive avoidance learning and spatial learning. The second set of experiments focuses on social motivation in an affiliative context. The experiments use distress vocalizations under different conditions of isolation, running speed to gain access to a conspecific after varying degrees of social deprivation, and social preference for conspecifics which are different with respect to aggressiveness. The third set of experiments examines social motivation in an aggressive context using the resident/intruder paradigm for both males and females; the motivation is varied by changing the context in which the aggression occurs. All of the experiments on social motivation use the additive factors technique to tease apart effects on motivation from effect on perception or the response mechanism; generally this technique examines the behavior under varying degrees of motivation and predicts that if groups differ in social motivation, then they will differ in how their behavior is altered by alterations in the level of social motivation. All of the experiments have three groups; these are rats exposed to alcohol during all three trimester equivalents, rat treated in the same manner as the alcohol-exposed rats except that they are not exposed to alcohol, and rats that are not treated in any manner. It is predicted that alcohol-exposed female rats will have enhanced social motivation compared to control female rats and alcohol-exposed male rats will have decreased social motivation compared to control male rats.